Apparatus for distilling glycerin.



F. J. WOOD.

APPARATUS FOR DISTILLING GLYGEBIN. APPLICATION FILED AUG. 1 s, 1907.RENEWED OUT. 22, 1913.

1,098,543., Patented June 2, 1914.

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F. J. WOOD.

APPARATUS FOR DISTILLING GLYGERIN.

APPLICATION FILED AUG.13, 1907. RENEWED 00:13.22, 1913 Patented June 2,1914.

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JElttK J. WOOD, OF NEW YORK, l\T. 5Z1, ASSIGNOR T0 MARX & RAWOLLE, OFNEW YORK, N. Y., A CORPORATION OF NEW YORK.

APPARATUS FOR DISTILLING GLYCERIN.

application filed. August 13, 1907, eria1 No. 388,396. Renewed OctoberSpecification of Letters Patent.

Patented June 2, 1914.

as, 1913. Serial No. 796,730.

it In the treatment of fats and oils of animal or vegetable origin forthe purpose of breaking them up into their constituents, fatty acids andglycerin, it is customary, especially when the acids are to be used'forthe manufacture of soap, to employ an alkali, such as caustic soda orpotash dissolved in water. In the presence of an alkali and assisted byheat the water breaks up the fat into glycer1n and fatty acids, thelatter combinlngwlth the alkali to form soap which remains 1n solutionand is generally precipitated and separated therefrom by the addition ofsalt. The salt used for this purpose remains d ssolved in the aqueoussolution of the glycerin. The evaporation of this solution, known asspent lye, yields the soap lye crudeglycerm of commerce which usuallycontains 8 to 10% salt and greatly exceeds in amount the output ofcandle crude glycerin which is free from salt.

The primary object of my present invention is to provide improved meansfor distilling glycerin of the charactermentioned, that 18, g. ycerincontaining salt.

The invention is, however, also available for use in distilling anyliquid or material which is decomposable in distillation.

in Letters Patent No. 881,525, of March 10, 1908, issued on myapplication, I have set forth a process of distilling glycerin theessential feature of which is the multiple effect of a continuouscurrent or flow of steam, that is, utilizing a single column of steamfor successively combining with, and effecting the distillation of, theglycerin contained in a plurality of stills. This process has been foundin practice to effect a great saving in steam and consequently in fuel.Each of the stills shown and described in the Letters Patent referred toas furnishing appropriate means tor carrying out the process comprisesin its organization a still, proper, and a subjacent "lycerin tank or J.W001), of

l l I reservo1r from which the g ycerin is pumped to the top of tubesvertically disposed in the still, the glycerin falling by gravity andheated 1n its fall, and mingling with the steam a portion combiningtherewith in the form of vapor, after which the glycerin is condensedand the steam is conducted to a succeeding still. Stills of thisconstruction operate successfull when the glycerin is relatively free ofsalt, but when the glycerin .CODULIIIS a quantity of salt it has beenfound 1n practice that the columns of superheated steam coming intosudden contact with the gravltating columns of glycerin within theconfined area of the heated tubes quickly vaporize the glycerin anddeposit the salt on the walls of the tubes. This deposit forms a hardincrustation which increases with the continued use of the still andtends to clog the passage throu h the tubes.

- By my present invention these difliculties are etlectively overcome,the idea, broadly stated, comprehending the heating of the glycerinprior to its union with the steam, and providing improved means forenabling the steam-to be successively utilized without superheatingprior to each distillation, the manner of the subsequent union of theglycerin and steam and the lines of travel of the combined vaporsobviating the possibility of salt depositing on a heatin sur face andatl'ording means for se aratlng it from the glycerin and withdrawing itfrom the distillation system.

In the accompanying drawin T have shown in Figure 1 a conventionalarrangement of the system. lFi 2 is a vertical sectional view of one oft e stills, the stea n superheater, "lycerin heater and the glycermcondenser. ig. 3 is a perspective view of one ol the stills broken away.

Referring to the drawings, 1 designates a steam boiler having its steamspace in communication with the heating space 2 of an evaporator 3, thevaporspace t or which in turn is open to the heating space 5 ot a secondevaporator 6, the heating spaces 2 and 5 having suitable outlets 7 forwater nit condensation and outlets 7 for gl cerin. From evaporator 6 apipe 8 leads to tie first of the stills 9, a steam superheatcr 10 beingshown arranged at a point 1n pipe near the still and communicating by apipe Iii? with the steam space of the boiler. This superheater, however,may be dispensed with it the steam is dry.

The still constitutes at its lower portion a l reservoir or receptaclefor glycerin supplied at 9, the liquid being indicated at 15, al thoughmuch more than the amount indicated may be supplied. An outlet pipe 16is shown leading from beneath the body of liquid into the still near itstop above the entrance point of the steam pipe 8. Glycerin is forcedthrough pipe 16 by the action of a centrifugal pump indicated at 17.

18 designates a glycerin heater to which high pressure steam is suppliedfrom the boiler through pipe 19 shown as a branch of pipe 12. Byreference to Fig. 3 of the drawings it will be seen that the glycerinpipe 16 is provided at the extremity thereof projecting into the stillwith a nozzle 20 which is curved so that the glycerin issuing therefromwill be directed tangentially against the cylindrical wall of the stilland thus caused to circulate within the still. The steam pipe 8 isdesigned to deliver steam into the still in the same direction, forwhich purpose it may be equipped with a nozzle like that of the glycerinpipe, or in lieu thereof a deflector plate 21 may be mounted in thestill as shown in Fig. 3. Intermediate the entrances of the steam andglycerin pipes, and disposed transversely of the still, is an annularledge 22 affording a central passage way 23, the inner edge of the ledgebeing serrated as shown at24. From the top of the still 9 a pipe 25leads to the glycerin condenser 26.

The glycerin condenser comprises a hot water condenser indicated at 27,having vertical tubes 35 forming vapor passages surrounded by hot watersupplied at 28, and a subj acent glycerin distillate tank 29 having anoutlet pipe 30 leading to a suitable vessel 31. From points above thewater line in the condensers pipes A are shown leading to a pipe Bopening into the steam pipe 8, abranch C extending to either or both ofthe evaporators 3, 6, and having suitable valves controlling thepassages. A pressure regulator D is shown in pipe B. Within tank 29 isan entrainment receptacle 32 also provided with an outlet pipe 33 andreceiving vessel 34 in communication with the still. The entrainmentreceptacle 32 is separated at all points from the glycerin distillatetank 29 and terminates at its upper end well short of the tubes 35 ofthe condenser. An inverted U-shaped deflector 36 has its bridge portioninterposed between the top of the receptacle 32 and the condenser 27,its laterals 38 extending down into the space between, tank 29 andreceptacle 32. The bridge portion or top of the deflector 36 is dishedas at 36* to form a receiver for the condensed glycerin which passesfrom tubes 35 through pipe 27 to a vessel 27*. The pipe 25 by whichsteam and glycerin vapors 'latter continuing to the succeeding still areconveyed from the still passes through-the walls of the parts 29, 32,and into the entrainment receptacle, its extremity being bentdownwardly.

The darts a indicate the line of direction of the vapors from pipe 25to'and through the condenser and darts Z) indicate the direction of theglycerin condensing in tank 29 and also the return of the condensedglycerin from the tubes 35 and their passage to vessel 27*. Thetemperature of the water in the condenser is such to condense theglycerin while maintaining the steam. the

37, which as well as the glycerin heater and the condenser, areconstructed and operate like the corresponding parts described, savethat a steam superheater is not necessary at the succeedingdistillations. The outlet from the last of the glycerin condensersconnects with a glycerin and steam condenser 39 which is supplied withcold water and communicates with evaporator 23 to supply sweet waterthereto. Condenser 39 is also in communication through pipe 40 with thevacuum pump 41.

In operating the distillation system the vacuum pump is operated tocreate a vacuum of about 28 inches in the stills, evaporator 6 and thetubes of the glycerin condensers. By adjusting the pressure regulator Dthe vacuum in the hot water spaces of the glycerin condensers is reducedto about 16 inches so that the water will boil at about 175 degrees F.This pressure will insure the glycerin fully condensing whilemaintaining the steam at high temperature. To obtain this temperature apressure of about 7 pounds absolute or vacuum of about 16 inches in pipeB is essential. The weight on the regulator D is therefore adjusted sothat with 28 inches of vacuum, or, 1 pound absolute, inthe stills, thevalve will be seated as against a pressure of 7 pounds or less in pipeB. When the operationof the vacuum pump is begun it exhausts the airfrom the stills and condenser tubes and the parts communicatingtherewith, but the pressure in pipes A and B and the hot water spaces ofthe condensers will not be affected by reason of the weight holding theregulator valve seated. But when the pressure in the stills reachesabout 6.7 pounds (the approximate difference in the pressures) thepressure in pipe B will unseat the valve. The further lowering ofpressure in the stills continues to lower that in pipe B but thedifference of approximately 6.7 pounds be tween the two pressuresremains constant. Consequently when a vacuum of 28 inches in the stillsis attained the vacuum in pipe B will be about 16 inches.

Each of the stills is supplied with crude glycerin 15 which is forced bythe centrifugal pump 17 through the heaters 18 to each of which steamunder about 175 pounds preswill ltd

till

menses sure is supplied through pipe 12. The glyccrin enters the stillin a highly heated condition but not sufliciently so as to occasion itsdecomposition, and not having been brought into contact with steamdurin': its passage through the heaters the salt will not deposit on theheating surface but will be carried in solution or suspension into thestill and the two elements will circulate therein above the annularledge 22. The glycerin and impurities will gravitate through opening 23over the serrations 24 which will tend to create divided columns. Whilethe glycerin is taking this course through the still after enteringabove the ledge the steam from evaporator 6, superheated at 10 by steamat L pounds pressure supplied to the superheater from the boiler, isentering the still below the ledge and circulating therein. his thesteam vapors follow their natural course toward the outlet pipe 25 theypass from beneath the-ledge and up through passage 23 and in taking thisline of direction they oncounter the divided streams or columns ofgravitating glycerin. This insures the effective physical association ofthe steam with the glycerin, resulting in vaporizing the glycerin andcausing its vapors to combine with and talie the direction of the steamupward to the exit pipe 25, the unvaporizeu glycerin and such of theimpurities as may not be carried up with the vapors tailing into thecrude glycerin 15 in the still to be again circulated through the pumpand heater and distilled in the further operation of the system. Fromthe stills the combined steam and glycerin vapors pass downward out ofpipe 25 into receptacle 32 where practically all ot the impuritiescarried up through the still as entrainment will fall, and passing outthrough pipe 33 to vessel 3 may be collected and removed or returned tothe still. in this connection it will be noted that the distillate tank29, by completely inclosing the entrainment receptacle 32, oper for thelatter to ates as a temperature shield maintain it heated, and that thisitunction is aided by the element 36 and the heated. vapors and lycerinpassing through the spaces between the parts 29, 3G and 32. in this waythe interior of the receptacle 32 is kept at such high temperature thatonly the cntrainment will be deposited therein, whereas it thisreceptacle were ex )osed to the atmosphere it would operate as a partialcondenser of the glycerin vapors. Hence I term receptacle 32 anon-condensing separator. The steam and glycerin vapors follow thecourse indicated by darts a to the condenser tubes where the glycerinvapors are the action ot the hot water in which the tubes 35 aresubmerged, the condensed glycerin then falling from the tubes into thebasin 36 and then to vessel 2'? as indicated by darts h. dome oil theglycerin, however, willcondense -,condenses after entering the thepresent invention possesses a liquefied by.

lowered from the condenser is directly in contact with the com binedsteam and glycerin vapors passing to the condenser yet this circumstancewill not affect the liquefied glycerinfor the reason that the steam iscarrying all the glycerin vapors which it can hold, and therefore itcannot absorb any of the condensed glycerin. On the other hand, as theglycerin quickly tubes '35, or moving a short distance upward therein,and then returns downward out of the tubes, its movement is confined tothe portion of the condenser in which the vapor and condensate arehottest and consequently its temperature is maintained too high to allowit to manitest its aihnity for the steam. In this respect the operationof the mechanism embodying vantage as compared with the described mannerof operating the mechanism shown in the Letters Patent- 881,525 asappropriate for carrying out the process therein covered. in the patentreferred to the course of the glycerin is shown and described as passingentirely through the tubes 7) and thus the glycerin might besuiliciently cooled upon issuing from the tubes to absorb some of thesteam. The greater part of the volatile impurities carried over with theglycerin vapors have a relatively low condensing temperature.Consequently but a small portion will condense on the walls of tank 29and for this reason the glycerin collected in the receiver 31 is offirst .uality while that collected in the vessel 27 1s of a lesserdegree of purity or second quality owing tothe fact that it will containmore of the volatile impurities condensed in the tubes 35.

' When the glycerin vapors condense they give up to the watersurrounding the tubes 35 the heat which they have taken from the highpressure steam in heater 18. This water, therefore, in the presence ofthe vacuum oil 16 inches will boil at about 175 degrees F. and the steamthus generated may he allowed to accumulate in pipes A and ll where itmay be retained until any desired pressure is reached, by adjusting theregulator weight, and on reaching this pressure it will pass to pipe 8for use in the stills or through branch C to either or both of theevaporators. Again, this steam may be a vailcd ot' in some oi themechanical devices as, tor instance, the operation of the pumps 17, anyof such uses tending to promote the economy of the system by lesseningthe amount of steam required of the boiler.

After leaving the glycerin condenser the steam relieved of most of itsglycerin con tents with its distilling value fully regained and changedonly by its temperature being highly superheated to distinct adimprovedmeans near the saturation point, passes on for use in the succeedingstills. This steam is dry and therefore additional superheating for eachsucceeding distillation is not necessary and only one superheater isillustrated. The functions of each of the stills and its respectiveglycerin heater and condenser are identical with those described. Thecondenser differs from the others in that it is supplied with cold waterto condense both the steam and glycerin. The sweet water passes to theevaporator 3 where the water is boiled out of the glycerin. This vapor Iprefer not to employ in the stills as it yet contains some volatileimpurities. I therefore conduct the vapor to the heating space 5 of theevaporator 6, the latter containing pure water which, by the action ofthe sweet water vapors, generates pure steam to be conducted throughpipe 8 to the stills.

From the foregoing it will be apparent that the essential steps of thedistilling process embraced by the Letters Patent referred to areperformed in the operation of the mechanism constituting the subject ofthis application. A single column of steam successively combines withand distils the glycerin contained in a plurality of stills. After eachdistillation glycerin is condensed out of the steam and the sweet waterfrom the final or steam and glycerin condenser may be, by the doubleeffect arrangement of the evaporators 3 and 6, utilized in generatingthe pure steam supplied to the stills. The salient distinctions,however, between the apparatus shown in the patent as appropriate forcarrying out the process, and that forming the subject of the presentcase, are thatwhere the former contemplates only the broadly novel ideaof the multiple efiect of a steam column in the art of glycerindistillation, the latter is directed to providing for carrying out theprocess under certain conditions as when salt is present in theglycerin, and specifically emhodies improved means for separately heating the glycerin when not in the presence of steam so that it will havebeen heated before mingling with the steam, instead of effecting theheating of both steam and glycerin at the time of their association, thelatter mode of treatment being productive of satisfactory results whenthe glycerin to be distilled is relatively pure.

The advantages of the single steam supply to a plurality of stills, overthe separate supplies thereto, and the manner of combining the steam andglycerin, as well as the physical laws which are invoked in thedistillation system, are apparent to those skilled l in the art and arefully set forth in the Letters Patent herein referred to. v 1

Vvhile I have specified glycerin as the ele ment for which the inventionis primarily adapted, yet it is available in any distilling Q systemWhere steam is necessary to assist distillation and where the element tobe distilled has a boiling point higher than that of water, such as theproducts of petroleum and coal tar, anilin, essential oils and fattyacids of the candle industry.

I claim as my invention 1. In an apparatus for distilling glycerin orsimilar material, a series of stills, means for conducting a singlecurrent. of steam successively through all of the said stills undersubstantially uniform pressure, a vertically disposed condenser for eachof said stills, means for conducting the glycerin vapors from a stillinto the lower portion of its respective condenser and upward therein,and means for collecting beneath said condenser the glycerin liquefiedtherein.

2. In an apparatus for distilling glycerin or similar material, a seriesof stills, means for conducting a single current of steam successivelythroughall of the said stills under substantially uniform pressure, aglycerin condenser for each of said stills; means for conducting theglycerin vapors from a still upward into its respective condenser, meansfor collecting beneath said condenser the glycerin liquefied therein,and means for conducting the steam from said glycerin condenser to thesucceeding still.

3. In an apparatus for distilling glycerin, a series of stills, meansfor causing a column of glycerin to flow through each of said stills,means for conducting a single current of steam successively to each ofsaid stills and passing it therethrough in a direction which intersectsthe column of glycerin flowing therein, and means for condensing theglycerin vapors of each flowing column.

4. In a glycerin distilling apparatus, a series of stills, a heater foreach of said stills, means for conducting glycerin to said heaters andthence to said stills, means for causing the glycerin entering each ofsaid stills to flow in a column, and means for conducting a singlecurrent of steam successively to each of said stills and toumns ofheated glycerin therein, and means for condensing the glycerin vapors ofeach flowing column.

5. In a glycerin distilling apparatus, a still, a glycerin condenserhaving vapor passages and a hot water space surrounding said passages,means for vaporizing glycerin in said still, means for conducting theglycerin vapors from said still upward through said condenser passages,means for collecting the liquefied glycerin and means for conductingfrom the hot water space of said condenser the steam generated thereinby the condensation of the glycerin vapors.

6. In a glycerin distilling apparatus, a still, a glycerin condenserhaving vapor passages and a hot water space surrounding said passages,means for mingling steam the flowing coland glycerin in a heatedcondition in said still, means for conducting the steam and glycerinvapors from said still upward a glycerin condenser having vapor passagesand a hot water space surrounding said passages, a vacuum pump andconnections between the latter and said still and said glycerincondenser, and means for maintaining a lower degree of vacuum in the hotwater spaceof said condenser than in said still.

8. In a glycerin distilling apparatus, a

still, ,means for vaporizing glycerin therein,

a glycerin condenser having vapor passages and a hot water spacesurrounding said pas sages, a pipe connection between said hot waterspace and the distillation system, and

a pressure regulator in said for the purpose stated I 9. In a glycerindistilling apparatus, a still, a glycerin heater, and means forconducting glycerin from said heater to said still and causing it togravitate and circulate therein.

10.- In a glycerin distilling apparatus, a still having an outlet at itstop, a glycerin heater, means for conducting glycerin from said heaterto said still and'causingit to gravitate and circulate therein, a steampipe entering said still beneath the entrance point of the glycerin anddesigned to discharge and direct'the steam so that it will circulate insaid still, whereby the steam in its passage to said outlet willencounter the gravitating glycerin.

11. In a glycerin distilling apparatus, a still having an outlet at itstop, a glycerin heater, means for conducting glycerin from said heaterto said still and causing it to gravitate and circulate therein, anannular ledge within said still beneath the entrance point oftheglycerin, and a steam pipe entering said still below saidcledge.

12. In a glycerin distilling apparatus, a still having an outlet at itstop, a glycerin heater, means for conducting glycerin from pipeconnection .said heater to said still and causing it to gravitate andcirculate therein, an annular ledge within said still beneath theentrance point of the glycerin, sald ledge having its inner free edgeserrated, and a steam pipe entering said still below said ledge.

' 13. Ina glycerin distilling apparatus, a still havinga crude glycerinreceptacle, a glycerin heater, a pipe leading from said receptacle tosaid heater, a pump fonforcing glycerin therethrough, and a pipe leadingfrom said heater into said still.

l-l. In a glycerin distilling apparatus, a still, means for forcingheated glycerin into said still and causing it tofiowiin gravitat ingcolumns, a steam supply entering said still beneath the point"of-introduction'of the glycerin, and a superheater located in saidsteam supply.

15. In a glycerin distilling apparatus, a still, means for vaporizingglycerin therein, an entrainment receptacle or non-condensing separatorin communication with saidstill, and a glycerin condenser incommunication with said entrainment receptacle.-

16. In a glycerin distilling apparatus, a still, means for vaporizingglycerin therein, an entrainment receptacle, a connection between saidstill and said receptacle, a casing inclosing said receptacle,andagly'cerin condenser in communication with said receptacle.

17. In a glycerin distilling apparatus, a still, means for vaporizingglycerin therein, an entrainment receptacle, a connection be.-

tween said still and said receptacle, a casn inginclosing saidreceptacle, and'separated therefrom at all points, and a glycerincondenser, the space between said casing and said receptacle affordingmeans of communication between the latter and said condenser.

18. In a glycerin distilling apparatus, a still, means for vaporizingglycerin therein, an entrainment receptacle in communication with saidstill and open at its top, an inverted U-shaped deflector having itsbridge .portion above the top of said receptacle and its parallelmembers extending downwardly over, but out of contact with, saidreceptacle, a casing inclosing said receptacle and deflector, and aglycerin condenser above said casing.

'19 In a glycerin distilling apparatus, a still, means for vaporizingglycerin therein, an entrainment receptaclein communication with saidstill and open at its top, an inverted U-shaped deflector having itsbridge portion above the top of said receptacle and its parallel membersextending downwardly over, but out of contact with, said receptacle,

said deflector constituting a distillate basin having a receiving andcollecting vessel, a distillate tank inclosing said receptacle anddeflector, and a glycerin condenser above said tank. I

20. In a glycerin distilling apparatus, a series of stills and alternateglycerin condensers, each of said stills being designed to contain abody of glycerin, connections between each of said stills and itsrespective condenser and each of said condensers and a the succeedingstill whereby a line of communication is provided throughout the systemout of contact with the respective bodles lll) of glycerin, a steamsupply passing through.

said line of communication, and means for withdrawing glycerin from eachof said stills and returning it thereto in a gravitatdensers and thesucceeding still, a steam and glycerin condenser in the series thereof,and

a sweet water evaporator in communication with said steam and glycerincondenser.

22. In a glycerin distilling apparatus,

ter, and means-for conducting the vapors fromthe sweet Water evaporatorto the steam space ofsaid pure water evaporator.

23. In a glycerin distilling apparatus designed to efiect a series ofglycerin distillations by the successive action of a single currentofsteam, a series of stills each designed to contain a body of glycerin,means for conducting a steam current'through said series of stills andupwardly through and around in each of said stills, out of contact withthe body of glycerin therein, means for withdrawing glycerin from eachof said stills and heating it and introducing it to the still above theentrance point of said steam E current in a circular line of direction,and

means forvaporizing glycerin by the action; of steam, means forcondensing the steam and glycerln vapors, an evaporator having a waterspace and a steam space, means for conducting the sweet Water from thesteam and glycerin condenser to the water space i of said evaporator,means for supplying;

a second evaporator having a steam space and a-water space deslgned tocontain pure wasteam to the steam'space of said evaporator, 1

means for dividing said glycerin into a series of columns in the path ofthe steam current. In testimony whereof, I have signed thisspecification in the presence of twosubscribing witnesses.

' FRANK J. WOOD- Witnesses:

GRAFTON L. MoGILL, ALICE D.- LIND.

